The present invention relates to an apparatus and a method to objectively measure sensory discrimination thresholds by delivering a time and pressure controlled air puff to the upper aero digestive tract, including, for example, the oral cavity, pharynx, or supraglottic larynx of a patient.
Within this application several publications are referenced by arabic numerals within parentheses. Full citations for these and other references may be found at the end of the specification immediately preceding the claims. The disclosures of all of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains.
There is a dearth of published studies of supraglottic and pharyngeal sensation in normal healthy controls, in the elderly, or in those who have suffered from a cerebrovascular accident (CVA). One of the primary problems with measuring sensation in this region (the area innervated by the superior laryngeal nerve) is the presence of the gag reflex and the relative inaccessibility of this area in awake individuals. These obstacles preclude standard sensory discrimination tests such as static and moving two point discrimination, vibratory testing, and stereognosis (1).
Knowledge of pharyngeal and supraglottic sensory discrimination thresholds is particularly important since hypesthesia or anesthesia in this area of the head and neck can cause severe dysphagia and an increased frequency of aspiration. Dysphagia and aspiration are commonly seen in the elderly (2), in those who have suffered a stroke (3), and in patients who have had ablative cancer surgery of the pharynx and larynx (4, 5) and/or loss of cranial nerves. The development of treatment modalities which address the sensory deficits in the pharynx and larynx is dependent upon defining and quantifying the sensory deficits in this region. The first step towards this goal is to establish normal thresholds for sensory discrimination.
However, as of yet, it appears that no one has been able to achieve this first step of measuring pharyngeal sensation in healthy control subjects, much less than in stroke patients with dysphagia. In other medical fields, air pulse stimulation of the cornea, or pneumatic tonometry has been used by ophthalmologists in order to measure intraocular pressure (6). Sensory discrimination testing using this technique, however, was not applied to the cornea. Air pulse stimuli have also been used as a natural stimulus to study the mechanisms whereby somatosensory systems analyze sensory stimulus patterns (7, 8). Furthermore air pulse stimuli have been shown to be an extremely sensitive and reliable method of determining sensory discrimination thresholds in the upper extremity of man (8, 9). However, it appears that no previous method of sensory testing of the upper aero digestive tract, including specifically the oral cavity, supraglottic larynx, or pharynx has been described.
It is an object of the present invention to provide an arrangement for testing and determining the sensory discrimination threshold in an individual at a test site in the upper aero digestive tract.
It is a further object of the present invention to provide an arrangement for testing and determining the supraglottic and pharyngeal sensory discrimination threshold in an individual.
It is a further object of the present invention to provide an arrangement for testing and determining the supraglottic and pharyngeal sensory discrimination threshold in an individual without causing excessive gagging.
It is a yet further object of the present invention to provide an arrangement for testing and determining the supraglottic and pharyngeal sensory discrimination threshold in an individual during an otherwise standard laryngoscopic examination.
According to one aspect of the present invention, an apparatus for testing sensation in a patient at a test site in the upper aero digestive tract is provided, comprising means for generating a time and pressure controlled puff of air and means, connected to said means for generating, for delivering the controlled puff of air to the test site.
According to another aspect of the present invention, an apparatus for testing pharyngeal and supraglottic sensation in a patient at a test site in the pharynx or larynx region is provided, comprising means for generating a time and pressure controlled puff of air and means, connected to said means for generating, for delivering the controlled puff of air to the pharynx or larynx region.
According to another aspect of the invention, an apparatus for testing sensation in a patient at a test site in the upper aero digestive tract is provided, comprising a Y-shaped tube with an inlet branch having an inlet end and first and second outlet branches having respective first and second outlet ends, the first outlet branch of the Y-shaped tube being inserted into the patient""s nasal passage and the first outlet end terminating adjacent the test site. A pressure transducer is connected to the second outlet branch of the Y-shaped tube, axially aligned with the second outlet end, means for delivering a time and pressure controlled puff of air to the inlet end of the Y-shaped tube is provided, as well as display means responsive to the pressure transducer for displaying the value of pressure detected by the transducer.
According to another aspect of the present invention, an apparatus for testing sensation in a patient at a test site in the upper aero digestive tract is provided, comprising a Y-connector with an inlet end and first and second outlet ends, a pressure transducer, means for delivering a time and pressure controlled puff of air to the inlet end of the Y-connector, a delivery tube with an inlet end and an outlet end, the delivery tube inlet end being connected to the first outlet end of the Y-connector and the delivery tube outlet end being inserted into the patient""s nasal passage and terminating adjacent the test site, a sensor tube with an inlet end and an outlet end, the sensor tube inlet end being connected to the second outlet end of the Y-connector and the sensor tube outlet end being connected to the pressure transducer, and display means responsive to the pressure transducer for displaying the value of pressure detected by the transducer.
According to another aspect of the present invention, an apparatus for testing sensation in a patient at a test site in the upper aero digestive tract is provided, comprising a flexible fiberoptic telescope inserted at its distal end into the patient""s nasal passage, the distal end terminating adjacent the test site, a Y-connector with an inlet end and first and second outlet ends, a delivery tube with an inlet end and an outlet end, the delivery tube being attached to the fiberoptic telescope with the outlet end of the delivery tube adjacent the distal end of the fiberoptic telescope and the inlet end of the delivery tube extending outside the patient and being attached to the first outlet end of the Y-connector, a pressure transducer, a sensor tube with an inlet end and an outlet end, the sensor tube inlet end being connected to the second outlet end of the Y-connector and the sensor tube outlet end being connected to the pressure transducer, means for delivering a time and pressure controlled puff of air to the inlet end of the Y-connector, and display means responsive to the pressure transducer for displaying the value of pressure detected by the transducer.
According to another aspect of the present invention, a method for testing sensation in a patient at a test site in the upper aero digestive tract is provided, comprising generating a time and pressure controlled puff of air and delivering the controlled puff of air to the test site.
According to another aspect of the present invention, a method for testing pharyngeal and supraglottic sensation in a patient at a test site in the pharynx or larynx region is provided, comprising generating a time and pressure controlled puff of air and delivering the controlled puff of air to the pharynx or larynx region.
According to another aspect of the present invention, a method for testing pharyngeal and supraglottic sensation in a patient at a test site in the pharynx or larynx region is provided, comprising generating six blocks of time and pressure controlled puffs of air, each block including ten puffs of air, each succeeding puff of air in a block differing by a pressure of about 7.5xc3x9710xe2x88x922 mm Hg as compared to the preceding puff of air, and delivering each block of time and pressure controlled puffs of air to the pharynx or larynx region, with a rest period between blocks of about 30 seconds.
According to another aspect of the present invention, a method for testing pharyngeal and supraglottic sensation in a patient at a test site in the pharynx or larynx region is provided, comprising inserting a first outlet end of a Y-shaped tube into the patent""s nasal passage adjacent the test site, delivering a time and pressure controlled puff of air to an inlet end of the Y-shaped tube, measuring the air pressure at a second outlet end of the Y-shaped tube, and displaying the measured air pressure.
These and other advantages will become apparent from the detailed description accompanying the claims and attached drawing figures.